Various sensing mechanisms employing switches have been widely used in many electronic devices in recent years. For instance, a typical sensing mechanism senses whether a shutter of a still camera is open or closed, or senses whether a display of a video movie camera is open or closed, or senses whether a disc remains in a FDD device or not.
As an element of the sensing mechanism, a variety of switches to be operated in different ways have been commercialized. For instance, an operating section of a switch is projected from a housing, and the projected section is tilted or pushed for changing the state of a contacting section placed in the housing. Removal of the operating force from the projected section will return the operating section to its original place.
Such a conventional switch is described hereinafter with reference to FIG. 10, which shows a perspective appearance of the conventional switch. In FIG. 10, housing 1 made of insulating resin has a recess open upward, and the opening is covered by cover 2. The recess accommodates a contacting section (not shown) of a self-reset switch. Operating lever 3 made of insulating resin and shaped like a straight rod protrudes upward slantingly, as an operating section of the switch, from the front section of housing 1.
Operating lever 3 is unitarily formed with an operating unit (not shown) accommodated in housing 1, and both of those elements form an operating member. A fulcrum section of the operating unit is rotatably supported in housing 1. The foregoing structure allows this conventional switch to tilt downward along the arrow mark shown in FIG. 10.
Tilting of lever 3 moves a pressing section of the operating unit, thereby changing a state of a contacting section placed in housing 1. Removal of the tilting force (operating force) returns the contacting section to its original location, and the recovery force returns lever 3 to its original state, i.e. in a slanting posture.
One of the prior art arrangements is disclosed in Japanese Patent Publication No. 2001-184994.
Since electronic devices have been downsized recently, the switches used therein have been required to be downsized. In particular, the switches used in the sensing mechanisms are required to be smaller in appearance, and to change a switch-state using a light operating force. On the other hand, since the switches are used in situations in which they are operated repeatedly, durability under frequent operation is required.
Under the foregoing circumstances, the conventional switches have been free from inconvenience and excellent in durability. However, when the device employing the switch is dropped, and an unexpected impact load is applied to an operating section (e.g. lever 3 in the foregoing case), the downsized operating section may be broken.